One function solution to text wrapping with fabricjs.

HTML

<canvas id="canvas" width="500" height="500"></canvas>
originally: http://www.maxenko.com/wrapping-text-for-fabric-js/

JavaScript

function wrapCanvasText(t, canvas, maxW, maxH, justify) {

    if (typeof maxH === "undefined") {
        maxH = 0;
    }
    var words = t.text.split(" ");
    var formatted = '';

    // This works only with monospace fonts
    justify = justify || 'left';

    // clear newlines
    var sansBreaks = t.text.replace(/(\r\n|\n|\r)/gm, "");
    // calc line height
    var lineHeight = new fabric.Text(sansBreaks, {
        fontFamily: t.fontFamily,
        fontSize: t.fontSize
    }).height;

    // adjust for vertical offset
    var maxHAdjusted = maxH > 0 ? maxH - lineHeight : 0;
    var context = canvas.getContext("2d");


    context.font = t.fontSize + "px " + t.fontFamily;
    var currentLine = '';
    var breakLineCount = 0;

    n = 0;
    while (n < words.length) {
        var isNewLine = currentLine == "";
        var testOverlap = currentLine + ' ' + words[n];

        // are we over width?
        var w = context.measureText(testOverlap).width;

        if (w < maxW) { // if not, keep adding words
            if (currentLine != '') currentLine += ' ';
            currentLine += words[n];
            // formatted += words[n] + ' ';
        } else {

            // if this hits, we got a word that need to be hypenated
            if (isNewLine) {
                var wordOverlap = "";

                // test word length until its over maxW
                for (var i = 0; i < words[n].length; ++i) {

                    wordOverlap += words[n].charAt(i);
                    var withHypeh = wordOverlap + "-";

                    if (context.measureText(withHypeh).width >= maxW) {
                        // add hyphen when splitting a word
                        withHypeh = wordOverlap.substr(0, wordOverlap.length - 2) + "-";
                        // update current word with remainder
                        words[n] = words[n].substr(wordOverlap.length - 1, words[n].length);
                        formatted += withHypeh; // add hypenated word
          ...